Answer this question truthfully
### Question: What causes Glaucoma?
### Response: The four major types of glaucoma have their own unique causes. However, before reviewing them, a brief overview of the anatomy of the eye may be helpful in understanding the causes of this disease:
The front part of the eye is filled with a clear fluid called aqueous humor. This fluid is always being made in the back of the eye. It leaves the eye through channels in the front of the eye in an area called the anterior chamber angle, or simply the angle. Anything that slows or blocks the flow of this fluid out of the eye will cause pressure to build up in the eye. This pressure is called intraocular pressure (IOP). In most cases of glaucoma, this pressure is high and causes damage to the major nerve in the eye, called the optic nerve.
More specific causes by each major type of glaucoma are:
Open-angle (chronic) glaucoma
The cause is unknown. An increase in eye pressure occurs slowly over time. The pressure pushes on the optic nerve and the retina at the back of the eye. Open-angle glaucoma tends to run in families. Your risk is higher if you have a parent or grandparent with open-angle glaucoma. People of African descent are at particularly high risk for this disease.
Angle-closure (acute) glaucoma
It occurs when the exit of the aqueous humor fluid is suddenly blocked. Dilating eye drops and certain medications may trigger an acute glaucoma attack.
Congenital glaucoma'
It is present at birth and results from the abnormal development of the fluid outflow channels in the eye. It is often hereditary and tends to run in families.
Secondary glaucoma
It is caused as complications of other medical conditions and/or procedures, including eye surgery, advanced cataracts, eye injuries, certain eye tumors, and uveitis. It can be caused by drugs such as corticosteroids, which are used to treat eye inflammations. Pigmentary glaucoma is caused when pigment from the iris breaks off, thereby slowing the fluid drainage and blocking the meshwork. Neovascular glaucoma is a severe form of secondary glaucoma that is linked to diabetes.